Integrated voltage regulator circuits usually include an Output Unit and a Regulating Unit. The input voltage is chopped by the Output Unit of switching power supply circuit into pulses, which is then transferred to the load after filtered. The Regulating Unit senses and regulates the output voltage. PSM (Pulse Skip Modulation) is often adopted in switching power supply circuit. The strategy of PSM control is that the output of a comparator determines this pulse skipped or not to regulate the output voltage by sampling the output voltage and comparing with the output reference voltage. PSM is based on CFCW (Constant Frequency Constant Width). Pulse will be skipped when output voltage is higher than reference voltage. Otherwise, output voltage is stable under CFCW control. At the same time, with energy module under PSM control, the input energy can be constant by manipulating output voltage and duty cycle. It is the fundamental of MEPT system tracking load's minimum energy point.